We review the wide spectrum of findings in CRS including sacral agenesis and associated urogenital, anorectal and other spinal abnormalities using all imaging modalities (conventional radiography, fluoroscopic procedures, spinal ultrasound, computed tomography and magnetic resonance).
Fig. 8: Proposed diagnostic algorithm for CRS with multiple imaging modalities.
References: Dr. Laura Michell Paramo Garcia, Pediatric Radiology Fellow, Hospital Infantil de Mexico Federico Gomez, Ciudad de Mexico, Mexico 2019.
Prenatal ultrasound in diabetic mothers must be methodical and keep in mind the possibility of CRS. First trimester findings are non specific such as short CRL and increased nuchal translucency [4,9]. Second and third trimester findings include abrupt termination of the spine, abnormal lower extremity positioning, “shield like” appearing iliac bones, and the “Buddha pose” in which flexion contractures of the hip and knee joints result in a frog like positioning of the lower limbs. A detailed full organ system US must follow if CRS is suspected. Assessment of fetal position is imperative because malpresentation is common in CRS. Fetal MRI can prove of great support in delineating ossification centers and illustrate spinal cord abnormalities. MRI must be considered in obese patients and in patients with oligohydramnios [4,5,7,9].
Spinal, abdominal, and transfontanellar ultrasound is suggested as the first complementary postnatal imaging modality. Spinal ultrasound allows us to delineate cord termination Fig. 9 Fig. 10 . Abdominal ultrasound to record genitourinary abnormalities. Nuclear medicine must algo be considered in evaluating renal function.
Fluoroscopic contrast enhanced studies must be considered in further evaluation of GI or GU pathology such as duodenal atresia, malrotation Fig. 11 , renal agenesis Fig. 12 , horseshoe kidney Fig. 13 , hydronephrosis, vesicoureteral reflux, neurogenic bladder Fig. 14 , and Mullerian duct abnormalities Fig. 15 [9]. CT and MRI can also be directed towards evaluation of internal organs. Proper diagnosis in these cases can aid to accelerate treatment and prevent irreversible organ damage.
Conventional radiography as well as computed tomography (CT) are the studies of choice for complete osseous characterization. CT must always be used with caution and take into consideration radiation exposure in pediatric patients [5,9].
MRI is the imaging modality of choice for a complete evaluation of internal organs and musculoskeletal abnormalities, it’s only deterrent is that in pediatric patients it must be done with sedation under the care of an anesthesiologist. Sagittal T1 and T2 weighted spin-echo, sagittal short-tau inversion recovery (STIR), axial T1/T2 weighted images, and sagittal echo gradient (GRE) images of the lumbosacral and pelvic regions are recommended for protocol in dealing with CRS [2,5,9].